Cardholder-driven: Direct API

A merchant using the direct API model can also use the tokenisation
service. There are two integration options for the direct API use of tokenisation: one-step and two-step.

In the one-step model, the merchant must manage all aspects of collecting the cardholder details for the transaction, and continue to manage the collection of CVV for subsequent transactions.

The two-step model exists to allow a merchant, on an order by order basis, to decide whether to invoke the payment page or the direct API submission of tokenised card details.